331 |
Design colaborativo e o processo de desenvolvimento de dispositivos para reabilitação do membro superior / Collaborative design and the device development process for upper limb rehabilitationCasagranda, Kelin Luana January 2018 (has links)
As órteses de membro superior são dispositivos que auxiliam na reabilitação da mão e que tem como objetivo estabilizar, imobilizar, prevenir e corrigir deformidades, melhorando assim a função. O processo tradicional de confecção de órteses é realizado por meio do uso de termoplásticos de baixa temperatura, material moldado diretamente sobre o membro do usuário, sendo neste processo relatados inúmeros problemas, que envolvem desconforto durante o processo, alto custo e baixa adesão do paciente ao uso. O presente trabalho, portanto, teve por objetivo propor a construção de um framework com abordagem metodológica projetual para a produção de órteses de membro superior baseada no processo de design e design colaborativo, com auxílio de recursos de fabricação digital, como digitalização tridimensional e manufatura aditiva (impressão 3D). Através de uma pesquisa exploratória, foram discutidas questões relativas ao projeto de órteses de membro superior (MMSS) pela forma tradicional, utilizando termoplástico de baixa temperatura, e questões do processo de design no desenvolvimento de novos produtos a serem aplicadas do desenvolvimento de órteses utilizando a manufatura aditiva A coleta de dados contou com a participação dos principais personagens envolvidos no processo, usuários de órteses, Terapeutas Ocupacionais e Designers. Com base na técnica de card sorting e entrevistas, foi elaborado um framework da abordagem projetual para a criação de órteses utilizando processos de fabricação digital, de forma colaborativa. O framework ainda foi aplicado no desenvolvimento de uma órtese a fim de avaliar os resultados e melhorias levantadas durante a fase de entrevistas com profissionais e usuários. Ao final do processo, obteve-se uma órtese funcional em que foram atendidos os requisitos necessários para a produção de uma órtese levantada pelo trabalho, além da criação do framework servindo como um guia para o desenvolvimento de órteses utilizando a manufatura aditiva. / Upper limb orthoses are devices that assist in the rehabilitation of the hand and that aim to stabilize, immobilize, prevent and correct deformities, thus improving the function. The traditional process of making orthotics is accomplished through the use of thermoplastics of low temperature, molded material directly on the member of the user, being in this process reported numerous problems, that involve discomfort during the process, high cost and low adhesion of the patient to the use. The present work, therefore, aimed to propose the construction of a framework with a design methodological approach for the production of upper limb orthosis based on the process of design and collaborative design, with the aid of digital manufacturing resources such as three - dimensional digitization and additive manufacturing (3D printing). Through an exploratory research, questions regarding the design of upper limb orthoses (MMSS) in the traditional way, using low-temperature thermoplastic, and design process issues in the development of new products to be applied in the development of orthoses using the additive manufacture The data collection was attended by the main characters involved in the process, users of orthoses, Occupational Therapists, and Designers. Based on the technique of card sorting and interviews, a framework of the design approach for the creation of orthoses using digital manufacturing processes was developed in a collaborative way. The framework was also applied in the development of a bracing in order to collaborate with the results and improvements raised during the interviews phase with professionals and users. At the end of the process, a functional orthosis was obtained, in which the necessary requirements for the production of an orthosis were obtained by the work, besides the creation of a framework serving as a guide for the development of orthoses using the additive manufacture.
|
332 |
Corrosion and Sensitized Microstructure Evolution of 3D Printed Stainless Steel 316 and Inconel 718 Dissolvable SupportsJanuary 2018 (has links)
abstract: Additive manufacturing (AM) describes an array of methods used to create a 3D object layer by layer. The increasing popularity of AM in the past decade has been due to its demonstrated potential to increase design flexibility, produce rapid prototypes, and decrease material waste. Temporary supports are an inconvenient necessity in many metal AM parts. These sacrificial structures are used to fabricate large overhangs, anchor the part to the build substrate, and provide a heat pathway to avoid warping. Polymers AM has addressed this issue by using support material that is soluble in an electrolyte that the base material is not. In contrast, metals AM has traditionally approached support removal using time consuming, costly methods such as electrical discharge machining or a dremel.
This work introduces dissolvable supports to single- and multi-material metals AM. The multi-material approach uses material choice to design a functionally graded material where corrosion is the functionality being varied. The single-material approach is the primary focus of this thesis, leveraging already common post-print heat treatments to locally alter the microstructure near the surface. By including a sensitizing agent in the ageing heat treatment, carbon is diffused into the part decreasing the corrosion resistance to a depth equal to at least half the support thickness. In a properly chosen electrolyte, this layer is easily chemically, or electrochemically removed. Stainless steel 316 (SS316) and Inconel 718 are both investigated to study this process using two popular alloys. The microstructure evolution and corrosion properties are investigated for both. For SS316, the effect of applied electrochemical potential is investigated to describe the varying corrosion phenomena induced, and the effect of potential choice on resultant roughness. In summary, a new approach to remove supports from metal AM parts is introduced to decrease costs and further the field of metals AM by expanding the design space. / Dissertation/Thesis / Doctoral Dissertation Mechanical Engineering 2018
|
333 |
Metodologia para adoção de sistemas de gestão baseada na ISO 9001 em organizações de manufatura aditiva aplicadas à saúde / Methodology for adoption of management systems based on ISO 9001 in organizations in additive manufacturing applied to healthMartins, Ketinlly Yasmyne Nascimento 22 December 2015 (has links)
Submitted by Jean Medeiros (jeanletras@uepb.edu.br) on 2017-02-09T13:07:51Z
No. of bitstreams: 1
PDF - Ketinlly Yasmyne Nascimento Martins.pdf: 1577076 bytes, checksum: 14566b5f84570ea62ab8c044a3d13094 (MD5) / Approved for entry into archive by Secta BC (secta.csu.bc@uepb.edu.br) on 2017-02-09T21:39:42Z (GMT) No. of bitstreams: 1
PDF - Ketinlly Yasmyne Nascimento Martins.pdf: 1577076 bytes, checksum: 14566b5f84570ea62ab8c044a3d13094 (MD5) / Made available in DSpace on 2017-02-09T21:39:42Z (GMT). No. of bitstreams: 1
PDF - Ketinlly Yasmyne Nascimento Martins.pdf: 1577076 bytes, checksum: 14566b5f84570ea62ab8c044a3d13094 (MD5)
Previous issue date: 2015-12-22 / This study aimed to present a methodology for implementation of Quality Management Systems (QMS) based on ISO 9001 for Additive Manufacturing organizations (MA) in health. The research was motivated by the need that the 3D Technologies Laboratory (LT3D) of the Center for Strategic Technologies in Health - NUTES presented in improving the quality of processes it has played, through the implementation of a QMS. To achieve this goal, specific objectives in order to assist the implementation were developed. One was the application of a case study in Three-dimensional technologies division (DT3D) of Renato Archer's Information Technology Center (CTI), which is certified by ISO 9001. The Other was the creation of a system design showing all the activities necessary for the production of biomodel which is the product manufactured in LT3D through MA, and correlate with the requirements of ISO 9001: 2008, thereby facilitating the understanding of the whole process. Also it took place throughout the modeling of business process through management model by BPM Business Process (Business Process Management) through the BPMN notation (Business Process Model and Notation). The steps of the proposed methodology were guided to make clear the activities critical to implementing a QMS, this model differs from the others by having the step of a system design that correlates all business process events for the production of biomodel, with requirements ISO 9001: 2008 , making it easier to understand what you want to have as a focus for implementation of a QMS for Additive Manufacturing organizations in health. / Este estudo teve como objetivo apresentar uma proposta metodológica para implantação de Sistemas de Gestão da Qualidade (SGQ) baseada na ISO 9001 em organizações de Manufatura Aditiva (MA) em saúde. A pesquisa foi motivada pela necessidade que o Laboratório de Tecnologias 3D (LT3D) do Núcleo de Tecnologias Estratégicas em Saúde - NUTES, apresentou em melhorar a qualidade dos seus processos, por meio da implantação de um SGQ. Para atingir o objetivo, foram desenvolvidos objetivos específicos afim de auxiliar a implantação. Um deles foi a realização de um estudo de caso na Divisão de Tecnologias Tridimensionais (DT3D) do Centro de Tecnologia da Informação Renato Archer (CTI), a qual é certificada pela NBR ISO 9001. O outro foi a elaboração de um Projeto de Sistema que mostra todas as atividades necessárias para produção do biomodelos que são o produto fabricado no LT3D através da MA e as correlacionam com os requisitos da norma ISO 9001:2008, facilitando assim a compreensão de todo o processo. Foi elaborada ainda a modelagem do processo de negócio através do modelo de Gestão por Processo de Negócio BPM (Business Process Management), por meio da notação BPMN (Business Process Model and Notation). As etapas da proposta metodológica foram pautadas em deixar claras as atividades críticas para implantação de um SGQ. Este modelo se diferencia dos demais por apresentar a etapa de um projeto de sistema que correlaciona todos os eventos do processo de negócio para produção do biomodelo, com os requisitos da norma ISO 9001:2008, tornando mais fácil a compreensão do que se pretende ter como foco para implantação de um SGQ para organizações de Manufatura Aditiva em saúde.
|
334 |
Modelo de processo de avaliação para adoção de manufatura aditiva na indústria de alto valor agregado. / Process model to evaluate additive manufacturing adoption in high value added industries.Cauê Gonçalves Mançanares 13 May 2016 (has links)
Manufatura aditiva é um processo de fabricação de objetos que tem chamado a atenção de acadêmicos, empresas e órgãos de governo. Alguns setores específicos possuem demandas que podem ser mais bem atendidas com a utilização da manufatura aditiva na produção de peças de alto valor agregado. O problema prático que motiva a realização deste trabalho é a dificuldade enfrentada pelas empresas em avaliar as tecnologias de manufatura aditiva existentes para decisão de adoção ou não adoção delas em seus fluxos produtivos. A análise da situação atual na literatura indica que falta um modelo de processo específico de avaliação para adoção da manufatura aditiva na indústria de alto valor agregado. Visando preencher essa lacuna e propor uma solução para o problema identificado, este trabalho tem como objetivo a definição de um modelo de processo específico de avaliação para adoção de manufatura aditiva na indústria de alto valor agregado. Tal modelo é desenvolvido a partir de modelos de processo existentes para avaliar a adoção de outras tecnologias de manufatura avançada (Advanced Manufaturing Technologies - AMTs) e do levantamento das características específicas da manufatura aditiva. O modelo de processo de avaliação para adoção da manufatura aditiva na indústria de alto valor agregado proposto contempla nove passos para decidir sobre a adoção ou a não adoção da manufatura aditiva. A aplicabilidade do modelo proposto foi avaliada por meio de entrevistas com especialistas. A avaliação dos resultados indica que os passos e as atividades propostos no modelo contribuem para auxiliar na avaliação para adoção da manufatura aditiva na indústria de alto valor agregado. / Additive manufacturing is a manufacturing process that has gained attention of scholars, companies and government bodies. Some specific sectors have demands that can be better met with the use of additive manufacturing to produce high added value parts. The practical problem that motivates this work is the difficulty met by companies in assessing additive manufacturing technologies for decision to adopt or not adopt them in their production flows. The analysis of the current situation in the literature indicates a gap of a specific process model to evaluate the adoption of additive manufacturing in the high added value industry. To fill this gap and to propose a solution for the identified problem, this work has the goal to define a specific process model to evaluate the adoption of additive manufacturing in the high added value industry. This model is developed based on existing process models to evaluate the adoption of other Advanced Manufacturing Technologies and the study of specific characteristics of additive manufacturing. The model proposed contemplates nine steps to decide on the adoption or not adoption of additive manufacturing. The applicability of the proposed model was evaluated through interviews with experts. The evaluation of the results indicates that the steps and the activities proposed in the model contribute to assist in the evaluation of the adoption of additive manufacturing in high added value industry.
|
335 |
Desenvolvimento de nova tecnologia de manufatura aditiva baseado em formação seletiva de compósito / Development of novel technology of additive manufacturing based on selective composite formationMarlon Wesley Machado Cunico 17 June 2013 (has links)
Nos últimos anos, a aplicação de tecnologias de manufatura aditiva tem crescido, estendendo seus benefícios para áreas diversas, como saúde, e encurtando o tempo de desenvolvimento de produto. Contudo, são encontrados apenas fabricantes nacionais de versões \"open-source\" de baixo custo de tecnologias de modelagem por fusão deposição (FDM), não existindo desenvolvedor de uma tecnologia nacional. Em função disto, o objetivo principal deste trabalho é apresentar e validar uma nova concepção de processo de fabricação aditiva. Esta proposta consiste na geração seletiva de compósito de celulose e acrílico através de fonte coerente de luz UV. Para isto, foram realizados estudos referentes a duas áreas principais, desenvolvimento de material e validação da concepção de processo proposto. Para o desenvolvimento de material, foram estudados materiais fotopoliméricos a base de acrilatos de forma a ser obtida uma formulação de material adequada para ser validado o processo. Da mesma forma, a seleção do material celulósico empregado foi realizado a partir da caracterização de materiais celulósicos laminados (papéis) comumente encontrados no mercado. Adicionalmente, foi identificado potencial de viabilidade preliminar da proposta ao longo da caracterização do compósito, visto que foi avaliada a aderência entre camadas, resistência mecânica à tração, resistência à água e microestrutura do compósito. Após o desenvolvimento do material, foi desenvolvido o projeto preliminar do equipamento de validação da proposta, assim como a fabricação de um protótipo e sua calibração. Foram realizados estudos de otimização para implementação do projeto do sistema de posicionamento, assim como dimensionamento de \"error Budget\" e custo relativo de equipamento. Foi também desenvolvido sistema de deposição de material polimérico, sistema de polimerização e alimentação de material, sendo realizados estudos de caracterização e validação do processo proposto. Foram identificados os efeitos principais dos principais parâmetros de processo para a largura da linha de polimerização, interferência da formação de compósito para camadas anteriores e, por fim a construção de corpo de prova. Através destes estudos, foi possível identificar a viabilidade funcional da proposta, sendo observadas as vantagens e desvantagens desta nova concepção em relação aos principais processos de fabricação aditiva no mercado. / In recent years, the application of additive manufacturing technologies has grown, extending its benefits to diverse areas such as health, and shortening the time product development. However, national manufacturers are only found to provide versions of open-source and low cost FDM technologies, highlighting the absence of a national technology developer. Due to that, the main goal of this work is to present and evaluate a novel concept of additive manufacturing process. This proposal consists in selectively generate composite of cellulose and acrylic through a coherent UV light source. For this, studies have been conducted concerning two main areas, material development and validation of proposed process. For the development of material, we have studied photopolymeric materials based on acrylates so as to obtain a composition of material suitable for validating the process. Likewise, the selection of cellulosic substrate was made from the characterization of laminated cellulosic materials (sheet of paper) which are commonly found at market. Additionally, we identified the potential feasibility of the proposal along the preliminary characterization the composite, whereas it was evaluated the adhesion between layers, tensile strength, water resistance and microstructure of the composite. After development the material, it was developed a preliminary design of equipment for validation of proposal, in addition to fabricating and calibrating a prototype. Studies were performed to optimize and implement the mechanical design of the positioning system as well as sizing error Budget and relative cost of equipment. It was also developed the systems of poylmerization, photopolymeric material deposition, and feed of substrate, being conducted studies for the characterization and validation of proposed process. We identified the main effects of the main process parameters on the polymerization line width, interference of the formation of composite layers for and previous layers, and the construction of the test ix body. Through these studies, it was possible to identify the functional feasibility of the proposal, being observed the advantages and disadvantages of this novel design in comparison with the main additive manufacturing process in the market.
|
336 |
Manufatura aditiva da liga Ti-6Al-4V aplicada em uma biela automotiva / Additive manufacturing of the Ti-6Al-4V alloy applied to an automotive connecting rodSu, Wiliam Tean, 1986- 23 August 2018 (has links)
Orientador: Cecília Amélia de Carvalho Zavaglia, Maria Aparecida Larosa / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-23T16:17:14Z (GMT). No. of bitstreams: 1
Su_WiliamTean_M.pdf: 6069585 bytes, checksum: 37502918a2190ac353153a8e20d78e0c (MD5)
Previous issue date: 2013 / Resumo: Atualmente, o mercado automotivo tem buscado cada vez mais a redução de peso e aumento de resistência mecânica de seus componentes. Dentro deste contexto, este trabalho tem como objetivo verificar se uma biela automotiva feita da liga de titânio Ti-6Al-4V obtida pelo processo de manufatura aditiva chamado Sinterização Direta de Metais por Laser (DMLS) apresenta os mesmos resultados estruturais que uma biela de Ti-6Al-4V laminada e recozida (comercial) ou que uma biela feita de aço C70, bastante utilizada no mercado. A liga Ti-6Al-4V é utilizada principalmente nas áreas aeronáutica e biomédica, mas também possui aplicações na indústria automotiva, principalmente no segmento de alta performance, graças a fatores como boa resistência mecânica, excelente resistência à corrosão e baixa densidade. As características mecânicas e microestruturais de amostras da liga Ti-6Al-4V prototipada por DMLS e de amostras da liga Ti-6Al-4V laminada e recozida foram avaliadas e comparadas através de ensaios de tração e microdureza, de análises em microscópio óptico e eletrônico de varredura (para a verificação da microestrutura e da porosidade), de ensaios de difração de raios-X (DRX) (para a análise das fases presentes no material), da análise da composição química por espectroscopia de energia dispersiva (EDS) e da análise de densidade pelo princípio de Arquimedes. Bielas de Ti-6Al-4V também foram produzidas por DMLS e ensaios de tração experimentais foram realizados, simulando uma condição de contorno típica utilizada em desenvolvimentos de bielas pela indústria automotiva. Com base nos resultados experimentais, foram realizadas análises de elementos finitos utilizando a mesma condição de contorno dos ensaios, com o intuito de se obter uma correlação entre os resultados experimentais e os virtuais. De uma maneira geral, todos os resultados indicam que a biela de Ti-6Al-4V produzida pelo processo DMLS possui um comportamento estrutural similar à biela de Ti-6Al-4V laminada e recozida / Abstract: Nowadays, the automotive market has been looking for more and more lightweight and better strength components. In this context, the objective of this work is to verify if a connecting rod made of the titanium alloy Ti-6Al-4V produced by an additive manufacturing process named Direct Metal Laser Sintering (DMLS) would have equivalent structural results of a connecting rod made of rolled annealed Ti-6AL-4V or even the C70 steel (widely used on the market for this application). This Titanium alloy is primary used in aerospace and biomedical areas, but is also used in the automotive industry, especially on the high performance segment, due to factors like good mechanical strength, excellent corrosion resistance and low density. The mechanical and microstrutural properties of Ti-6Al-4V samples obtained by DMLS and rolling and annealing processes were compared through the realization of tensile and micro hardness tests and through the microstructural characterization, composed of scanning electron microscopy (microstructure verification), optical microscopy (porosity verification), X-ray diffraction analysis for phases quantification, energy dispersive spectroscopy (chemical composition verification) and density analysis using the Arquimedes principle. Ti-6Al-4V connecting rods were also produced by the DMLS process and tensile experimental tests were performed using the same boundary condition as commonly seen on connecting rod development at automotive industry. Based on the experimental results, finite element analyses were performed in order to correlate the experimental and the virtual results. Generally, all the results indicate that the Ti-6Al-4V connecting rod produced by DMLS process has a structural behavior similar to the Ti-6Al-4V connecting rod produced by rolling and annealing process / Mestrado / Materiais e Processos de Fabricação / Mestre em Engenharia Mecânica
|
337 |
The Effect of Alloys, Powder, and Overhanging Geometries in Laser Powder Bed Additive ManufacturingMontgomery, Colt James 01 December 2017 (has links)
Additive manufacturing (AM) shows great promise for the manufacturing of next-generation engineering structures by enabling the production of engineered cellular structures, overhangs, and reducing waste. Melt-pool geometry prediction and control is critical for widespread implementation of laser powder bed processes due to speed and accuracy requirements. The process mapping approach used in previous work for different alloys and additive manufacturing processes is applied to the selective laser powder bed process for IN625 and 17-4 stainless steel alloys. The ability to predict the resulting steady state melt-pool geometry in terms of process parameters, specifically power and velocity, is explored in detail numerically and experimentally verified. A finite element model was created that simulates powder at the macro scale. This model correlates well with current experiments in showing that small amounts of powder relative to melt-pool depth have negligible effects on resulting geometry. Results indicate that the effect of powder may be negligible when comparing steady state widths of the no powder and one layer of powder cases. The work in this thesis investigates the effect of powder on the resulting steady-state melt-pool geometries for IN625 and 17-4 alloys. This analysis has been extended to the production of overhanging and cellular structures. The successful analysis will allow for better predictions and possible correction for cellular structure production issues as well as overhanging features.
|
338 |
Commercializing Additive Manufacturing Technologies : A Business Model Innovation approach to shift from Traditional to Additive Manufacturing / Commercializing Additive Manufacturing Technologies : A Business Model Innovation approach to shift from Traditional to Additive ManufacturingLebherz, Matthias, Hartmann, Jonathan January 2017 (has links)
Additive Manufacturing is a fast-developing technology that is considered to be a game changer in the manufacturing industry. However, a technological innovation itself has no single objective value for a company. Indeed, it is widely acknowledged that the key aspect of a successful commercialization of a technological innovation is the linkage of the technology and the business model. Based on a qualitative study, which presents how companies have to develop their business model to commercialize AM, we conducted interviews with two Swedish small and medium-sized enterprises, which plan to invest in Additive Manufacturing. These two companies are HGF, a manufacturer of thermoplastic elastomers and rubber products, and Tylö, a manufacturer of heaters, steam generators, saunas, steam showers, and infrared saunas. In our analysis, we decided to analyse the cases successively, according to the nine building blocks of the Business Model Canvas. Firstly, we conducted a within-case analysis to analyse each case isolated from each other, and secondly a cross-case analysis to find possible nexuses, relations or, contrasts. The chapter conclusion provides an overall discussion of the most important findings emerging from the analysis with regard to the required changes within the current business model to capture value from the technology. We could find some disparities for two building blocks (channels and revenue streams). Thus, this implies that there is no universal approach to develop the business model to introduce Additive Manufacturing. Nevertheless, most of the required adjustments show accordance. While three building blocks turned out to remain largely the same (key partnerships, cost structure, and customer segments), four building blocks require important changes (key activities, key resources, value propositions, and customer relationships. The most important implications for those building blocks are presented in the following: Key activities: Upgrade product development Key resources: Establish additional production facilities (3D-printers, etc.) Gather new knowledge about AM Value propositions: Offer customized products Customer relationships: Closer relationship with the (end) customer Enhance customer co-creation
|
339 |
Large Area Sintering Test Platform Design and Preliminary Study on Cross Sectional ResolutionGardiner, Christopher J. 02 November 2017 (has links)
Additive manufacturing involves the layer-wise patterned addition of material to create 3D parts, allowing for parts with complex geometries that traditional subtractive manufacturing processes cannot create, while offering good value for low run production parts by eliminating the cost of tooling. Large Area Sintering is a form of powder based additive manufacturing where entire layer cross sections are heated and fused in a single continuous exposure process. This layer by layer powder sintering process is similar to selective laser sintering, but by heating the cross section at a slower and controllable rate there is an opportunity to achieve tighter control over thermal history. This thesis discusses the design, construction, and validation of a large area sintering test platform, as well as a preliminary study on feature resolution. A key component of this system was the integration of an infrared camera, allowing point-wise temperature control of the sintering cross section. There is a hypothesis that longer and controlled heating rates in Large Area Sintering (in comparison to Selective Laser Sintering) would allow the capability to process a wider range of materials, and give more control over the resulting final part properties. The test platform created a repeatable test environment, and successfully demonstrated the capability for point wise temperature control of the sintering cross section, enabling the ability to examine the effects of slower controlled heating rates. Available power on the system was 2.22 W/cm2 for heating, with a temperature control loop time of 160 – 180 ms. The results of the preliminary study on feature resolution also suggested a positive correlation between point wise closed loop temperature control and improved feature resolution, giving motivation for further study.
|
340 |
Part Temperature Effects in Powder Bed Fusion Additive Manufacturing of Ti-6Al-4VFisher, Brian A. 01 May 2018 (has links)
To ensure the widespread adoption of metal Additive Manufacturing (AM) processes, a complete understanding of the interactions between process variables is necessary. The process variables of beam power, beam velocity, deposition geometry, and beam diameter have been shown in prior works to have major effects on resultant melt pool and solidification characteristics, but this list is incomplete. Without accounting for part temperatures prior to deposition, unintended outcomes may result. In the current work, Ti-6Al-4V is studied in the Powder Bed Fusion (PBF) processes to gain an in-depth understanding of how part temperature interactions with other process variables affect physical properties of the process such as melt pool size and variability, part distortion, porosity, and microstructural characteristics. This research is performed through a combination of finite element modelling, single melt track experiments, full part production, and in-situ monitoring in order to gain a full understanding of the underlying relationships between part temperature and part outcomes. In the Arcam Electron Beam Melting (EBM®) process, this knowledge is used to generate a feedback control strategy to constrain prior beta grain width to remain constant while part surface temperatures are allowed to vary. In the Laser Powder Bed Fusion (LPBF) process, deposition is investigated at elevated substrate temperatures and several findings show that unintended part temperature increases can lead to undesirable consequences while prescribed part temperature changes can increase the available processing window and allow for more uniform deposition. This work also shows that both global temperature changes due to substrate heating and local temperature changes due to the choice of scan strategy can be combined into one metric: the temperature encountered by the melt pool during deposition. A combination of destructive and non-destructive characterization methods are utilized to understand and measure the changes to the melt pool and microstructural development that are seen during deposition. The feasibility of using a commercial high speed camera as a tool for thermography is characterized and the ability to discern cooling rates and thermal gradients within and surrounding the melt pool provide validation for trends in melt pool properties generated from simulations. This work provides a greater understanding of the role of part temperature during deposition and presents methodologies to account for the changes to the melt pool and resultant part due to both prescribed and unintended temperature changes during deposition.
|
Page generated in 0.0352 seconds